Printed-wiring boards to be used for electronic equipment such as computers are prepared by forming a determined pattern of wiring of copper or the like on one or both sides of an insulating substrate.
Printed-wiring boards of this kind may be prepared by the following manufacturing steps.
First, a laminated film consisting of a photosensitive resin (photoresist) layer and a translucent resin film (protective layer) protecting the photosensitive resin layer is laminated by thermocompression bonding on a conductive layer mounted on an insulating substrate. The lamination by thermocompression bonding may be conducted on a large scale using a film laminating apparatus or a so-called laminater. Thereafter, a wiring pattern film is superposed on the laminated film, and the photosensitive resin layer is exposed for a determined period of time through the wiring pattern film and the translucent resin film. After the translucent resin film is peeled off using a peeling device, the exposed photosensitive resin layer is developed to form an etching mask pattern. Thereafter, unnecessary portions of the conductive layer are removed by etching and further the remaining photosensitive resin layer is removed, thereby producing a printed-wiring board with a predetermined wiring pattern.
In the manufacturing steps of the printed-wiring boards as described above, it is necessary during the step of exposing the photosensitive resin layer to superpose the wiring pattern film on the laminated film laminated on the substrate by thermocompression bonding. This superposition is carried out by fitting a positioning pin in a guide hole (or a positioning hole) formed at a corner or end portion of the substrate and a guide hole (or a positioning hole) formed on the wiring pattern film so as to correspond to the above guide hole. Since the laminated film is laminated on the substrate, a hole for fitting the positioning pin is formed on the laminated film by punching at the position corresponding to the guide hole on the substrate prior to the fitting of the positioning pin. The punching of the laminated film may be effected manually using a drill or a punch or mechanically using a punching device for exclusive use after the laminated film has been laminated on the substrate by thermocompression bonding.
However, manual or mechanical punching of the laminated film causes problems, resulting in extremely poor work efficiency.
In forming a hole by punching the laminated film, chips of the laminated film are scattered on the laminated film on which a wiring pattern is formed and it is extremely hard to clear such chips. This prevents the wiring pattern from being drawn accurately on the photosensitive resin layer, resulting in decreased yield in the manufacture of printed-wiring boards.